| /* |
| * Copyright (c) 2008, Christoph Hellwig |
| * All Rights Reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it would be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| #include "xfs.h" |
| #include "xfs_format.h" |
| #include "xfs_log_format.h" |
| #include "xfs_trans_resv.h" |
| #include "xfs_mount.h" |
| #include "xfs_inode.h" |
| #include "xfs_acl.h" |
| #include "xfs_attr.h" |
| #include "xfs_trace.h" |
| #include <linux/slab.h> |
| #include <linux/xattr.h> |
| #include <linux/posix_acl_xattr.h> |
| |
| |
| /* |
| * Locking scheme: |
| * - all ACL updates are protected by inode->i_mutex, which is taken before |
| * calling into this file. |
| */ |
| |
| STATIC struct posix_acl * |
| xfs_acl_from_disk( |
| const struct xfs_acl *aclp, |
| int len, |
| int max_entries) |
| { |
| struct posix_acl_entry *acl_e; |
| struct posix_acl *acl; |
| const struct xfs_acl_entry *ace; |
| unsigned int count, i; |
| |
| if (len < sizeof(*aclp)) |
| return ERR_PTR(-EFSCORRUPTED); |
| count = be32_to_cpu(aclp->acl_cnt); |
| if (count > max_entries || XFS_ACL_SIZE(count) != len) |
| return ERR_PTR(-EFSCORRUPTED); |
| |
| acl = posix_acl_alloc(count, GFP_KERNEL); |
| if (!acl) |
| return ERR_PTR(-ENOMEM); |
| |
| for (i = 0; i < count; i++) { |
| acl_e = &acl->a_entries[i]; |
| ace = &aclp->acl_entry[i]; |
| |
| /* |
| * The tag is 32 bits on disk and 16 bits in core. |
| * |
| * Because every access to it goes through the core |
| * format first this is not a problem. |
| */ |
| acl_e->e_tag = be32_to_cpu(ace->ae_tag); |
| acl_e->e_perm = be16_to_cpu(ace->ae_perm); |
| |
| switch (acl_e->e_tag) { |
| case ACL_USER: |
| acl_e->e_uid = xfs_uid_to_kuid(be32_to_cpu(ace->ae_id)); |
| break; |
| case ACL_GROUP: |
| acl_e->e_gid = xfs_gid_to_kgid(be32_to_cpu(ace->ae_id)); |
| break; |
| case ACL_USER_OBJ: |
| case ACL_GROUP_OBJ: |
| case ACL_MASK: |
| case ACL_OTHER: |
| break; |
| default: |
| goto fail; |
| } |
| } |
| return acl; |
| |
| fail: |
| posix_acl_release(acl); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| STATIC void |
| xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl) |
| { |
| const struct posix_acl_entry *acl_e; |
| struct xfs_acl_entry *ace; |
| int i; |
| |
| aclp->acl_cnt = cpu_to_be32(acl->a_count); |
| for (i = 0; i < acl->a_count; i++) { |
| ace = &aclp->acl_entry[i]; |
| acl_e = &acl->a_entries[i]; |
| |
| ace->ae_tag = cpu_to_be32(acl_e->e_tag); |
| switch (acl_e->e_tag) { |
| case ACL_USER: |
| ace->ae_id = cpu_to_be32(xfs_kuid_to_uid(acl_e->e_uid)); |
| break; |
| case ACL_GROUP: |
| ace->ae_id = cpu_to_be32(xfs_kgid_to_gid(acl_e->e_gid)); |
| break; |
| default: |
| ace->ae_id = cpu_to_be32(ACL_UNDEFINED_ID); |
| break; |
| } |
| |
| ace->ae_perm = cpu_to_be16(acl_e->e_perm); |
| } |
| } |
| |
| struct posix_acl * |
| xfs_get_acl(struct inode *inode, int type) |
| { |
| struct xfs_inode *ip = XFS_I(inode); |
| struct posix_acl *acl = NULL; |
| struct xfs_acl *xfs_acl; |
| unsigned char *ea_name; |
| int error; |
| int len; |
| |
| trace_xfs_get_acl(ip); |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| ea_name = SGI_ACL_FILE; |
| break; |
| case ACL_TYPE_DEFAULT: |
| ea_name = SGI_ACL_DEFAULT; |
| break; |
| default: |
| BUG(); |
| } |
| |
| /* |
| * If we have a cached ACLs value just return it, not need to |
| * go out to the disk. |
| */ |
| len = XFS_ACL_MAX_SIZE(ip->i_mount); |
| xfs_acl = kmem_zalloc_large(len, KM_SLEEP); |
| if (!xfs_acl) |
| return ERR_PTR(-ENOMEM); |
| |
| error = xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl, |
| &len, ATTR_ROOT); |
| if (error) { |
| /* |
| * If the attribute doesn't exist make sure we have a negative |
| * cache entry, for any other error assume it is transient. |
| */ |
| if (error != -ENOATTR) |
| acl = ERR_PTR(error); |
| } else { |
| acl = xfs_acl_from_disk(xfs_acl, len, |
| XFS_ACL_MAX_ENTRIES(ip->i_mount)); |
| } |
| kmem_free(xfs_acl); |
| return acl; |
| } |
| |
| STATIC int |
| __xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl) |
| { |
| struct xfs_inode *ip = XFS_I(inode); |
| unsigned char *ea_name; |
| int error; |
| |
| switch (type) { |
| case ACL_TYPE_ACCESS: |
| ea_name = SGI_ACL_FILE; |
| break; |
| case ACL_TYPE_DEFAULT: |
| if (!S_ISDIR(inode->i_mode)) |
| return acl ? -EACCES : 0; |
| ea_name = SGI_ACL_DEFAULT; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| if (acl) { |
| struct xfs_acl *xfs_acl; |
| int len = XFS_ACL_MAX_SIZE(ip->i_mount); |
| |
| xfs_acl = kmem_zalloc_large(len, KM_SLEEP); |
| if (!xfs_acl) |
| return -ENOMEM; |
| |
| xfs_acl_to_disk(xfs_acl, acl); |
| |
| /* subtract away the unused acl entries */ |
| len -= sizeof(struct xfs_acl_entry) * |
| (XFS_ACL_MAX_ENTRIES(ip->i_mount) - acl->a_count); |
| |
| error = xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl, |
| len, ATTR_ROOT); |
| |
| kmem_free(xfs_acl); |
| } else { |
| /* |
| * A NULL ACL argument means we want to remove the ACL. |
| */ |
| error = xfs_attr_remove(ip, ea_name, ATTR_ROOT); |
| |
| /* |
| * If the attribute didn't exist to start with that's fine. |
| */ |
| if (error == -ENOATTR) |
| error = 0; |
| } |
| |
| if (!error) |
| set_cached_acl(inode, type, acl); |
| return error; |
| } |
| |
| static int |
| xfs_set_mode(struct inode *inode, umode_t mode) |
| { |
| int error = 0; |
| |
| if (mode != inode->i_mode) { |
| struct iattr iattr; |
| |
| iattr.ia_valid = ATTR_MODE | ATTR_CTIME; |
| iattr.ia_mode = mode; |
| iattr.ia_ctime = current_fs_time(inode->i_sb); |
| |
| error = xfs_setattr_nonsize(XFS_I(inode), &iattr, XFS_ATTR_NOACL); |
| } |
| |
| return error; |
| } |
| |
| int |
| xfs_set_acl(struct inode *inode, struct posix_acl *acl, int type) |
| { |
| int error = 0; |
| |
| if (!acl) |
| goto set_acl; |
| |
| error = -E2BIG; |
| if (acl->a_count > XFS_ACL_MAX_ENTRIES(XFS_M(inode->i_sb))) |
| return error; |
| |
| if (type == ACL_TYPE_ACCESS) { |
| umode_t mode; |
| |
| error = posix_acl_update_mode(inode, &mode, &acl); |
| if (error) |
| return error; |
| error = xfs_set_mode(inode, mode); |
| if (error) |
| return error; |
| } |
| |
| set_acl: |
| return __xfs_set_acl(inode, type, acl); |
| } |